Spacers and connectors for insulated glass units

ABSTRACT

This disclosure describes insulated glass units (IGUs) that incorporate electrochromic devices. More specifically, this disclosure focuses on different configurations available for providing an electrical connection to the interior region of an IGU. In many cases, an IGU includes two panes separated by a spacer. The spacer defines an interior region of the IGU and an exterior region of the IGU. Often, the electrochromic device positioned on the pane does not extend past the spacer, and some electrical connection must be provided to supply power from the exterior of the IGU to the electrochromic device on the interior of the IGU. In some embodiments, the spacer includes one or more holes (e.g, channels, mouse holes, other holes, etc.) through which an electrical connection (e.g., wires, busbar leads, etc.) may pass to provide power to the electrochromic device.

INCORPORATION BY REFERENCE

An Application Data Sheet is filed concurrently with this specificationas part of the present application. Each application that the presentapplication claims benefit of or priority to as identified in theconcurrently filed Application Data Sheet is incorporated by referenceherein in its entirety and for all purposes.

FIELD

The disclosed embodiments relate generally to spacers and insulatedglass units containing them, and more particularly to insulated glassunits including optically switchable devices.

BACKGROUND

Various optically switchable devices are available for controllingtinting, reflectivity, etc. of window panes. Electrochromic devices areone example of optically switchable devices generally. Electrochromismis a phenomenon in which a material exhibits a reversibleelectrochemically-mediated change in an optical property when placed ina different electronic state, typically by being subjected to a voltagechange. The optical property being manipulated is typically one or moreof color, transmittance, absorbance, and reflectance. One well knownelectrochromic material is tungsten oxide (WO₃). Tungsten oxide is acathodic electrochromic material in which a coloration transition,transparent to blue, occurs by electrochemical reduction.

Electrochromic materials may be incorporated into, for example, windowsfor home, commercial, and other uses. The color, transmittance,absorbance, and/or reflectance of such windows may be changed byinducing a change in the electrochromic material, that is,electrochromic windows are windows that can be darkened or lightenedelectronically. A small voltage applied to an electrochromic (EC) deviceof the window will cause it to darken; reversing the voltage causes itto lighten. This capability allows for control of the amount of lightthat passes through the window, and presents an enormous opportunity forelectrochromic windows to be used not only for aesthetic purposes butalso for energy-savings.

With energy conservation being foremost in modern energy policy, it isexpected that growth of the EC window industry will be robust in thecoming years. An important aspect of EC window engineering is how tointegrate EC windows into new and existing (retrofit) applications. Ofparticular import is how to deliver power to the EC glazings throughframing and related structures.

SUMMARY

Insulated glass units (IGUs) incorporating electrochromic devices aredisclosed herein. The disclosed IGUs include spacers that allow for anelectrical connection to be passed through or under the spacer toprovide power from an external power source to the electrochromic devicein the IGU.

In one aspect of the disclosed embodiments, an IGU includes a firstglass substrate; a second glass substrate oriented parallel to the firstglass substrate; an electrochromic device positioned on the first orsecond glass substrate; two bus bars electrically connected to theelectrochromic device; a spacer positioned between the first and secondglass substrates proximate the periphery of the first and second glasssubstrates, where the spacer defines an interior region of the IGUlocated interior of the spacer and an exterior region of the IGU locatedoutside of the spacer; and one or more wires passing through the spacerto provide electrical power from an external power source located in theexterior region to the bus bars and the electrochromic device in theinterior region of the IGU.

In certain embodiments the spacer may be hollow. Where this is the case,the wires may enter the hollow spacer at a first location, pass withinthe hollow interior of the spacer for a distance, and exit the spacer ata second location. In these or other cases, the spacer may include oneor more holes through which the one or more wires pass.

The spacer may include different parts, for example a conductive portionand an insulating or non-conductive portion. For example, the insulatingor non-conductive portion may be a connector key that joins the ends ofthe conductive portion together. In this embodiment, the one or morewires passing through the spacer may traverse the spacer at theinsulating or non-conductive connector key. The IGU may also include acontroller coupled to the IGU and configured to drive an electrochromictransition of the electrochromic device of the IGU.

In a particular embodiment, the spacer is a track having interiorrecesses for two or more electrical connections on the interior of thetrack and exterior recesses for two or more electrical connections onthe exterior of the track. The track may include one or more holesthrough the track for establishing a pass-through electrical connectionbetween the two or more electrical connections on the exterior of thetrack and the two or more electrical connections on the interior of thetrack, where the electrical connections on the interior of the trackprovide power to the bus bars, and where the electrical connections onthe exterior of the track provide power from an external power source.

In various implementations, the IGU includes a seal in a hole of thespacer through which the one or more wires pass. The wires passingthrough the spacer may be provided together as a braided wire. Where thespacer is hollow, a dessicant may be provided in the hollow interior ofthe spacer.

In another aspect of the disclosed embodiments, an IGU includes a firstglass substrate; a second glass substrate oriented parallel to the firstglass substrate; an electrochromic device positioned on the first orsecond glass substrate; two bus bars electrically connected to theelectrochromic device; a spacer positioned between the first and secondglass substrates proximate the periphery of the first and second glasssubstrates, where the spacer defines an interior region of the IGUlocated interior of the spacer and an exterior region of the IGU locatedoutside of the spacer; and one or more electrical connections passingthrough or under the spacer to provide electrical power from an externalpower source located in the exterior region to the bus bars and theelectrochromic device in the interior region of the IGU.

In certain embodiments, the IGU further includes a channel in or underthe spacer, through which the electrical connections pass from theinterior region of the IGU to the exterior region of the IGU. Forexample, the spacer may include an indented portion such that thechannel is defined on one side by the first or second glass substrate ora layer of material thereon, and on remaining sides by the indentedportion of the spacer as the channel passes from the exterior region tothe interior region of the IGU. The channel may have a height betweenabout 0.1-1 mm, in certain cases. The electrical connections may bewires that pass under (or through) the spacer. In other cases, theelectrical connections may be bus bar leads that pass under the spacer.A controller may be coupled to the IGU and configured to drive anelectrochromic transition of the electrochromic device on the IGU.

These and other features and advantages will be described in furtherdetail below, with reference to the associated drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1C show examples of schematic diagrams of electrochromicdevices formed on windows.

FIG. 2A shows a cross-sectional schematic diagram of an electrochromicwindow integrated into an IGU.

FIG. 2B is an additional cross-sectional schematic of an electrochromicdevice.

FIG. 3A depicts an example of an electrochromic window fabricationprocess.

FIG. 3B depicts an example of a window assembly.

FIG. 4 shows examples of three modes of potential shorting to the spacerand consequent failure of an electrochromic device in an IGU.

FIG. 5A shows an example of a cross-section of an edge region of an IGUwhere the spacer of the IGU and the bus bar reside.

FIG. 5B shows cross-sections of other spacers in accord with embodimentsdescribed herein.

FIG. 6 shows two embodiments of connector keys.

FIG. 7 shows an example of a detailed cross-sectional view of a crimpedconnector key aligned on a glass sheet with an electrochromic devicefabricated thereon.

FIGS. 8 and 9 show schematic diagrams of an insulated glass unitincluding an electrochromic pane and an associated wire assembly.

FIGS. 10A and 10B include schematic diagrams of an insulated glass unit(IGU) with a frame that may serve as both as a secondary sealing elementand an electrical connector for an electrochromic pane of the IGU.

FIGS. 11A and 11B show examples of IGUs with different wiringconfigurations.

DETAILED DESCRIPTION

It should be understood that while the disclosed embodiments focus onelectrochromic (EC) windows (also referred to as smart windows), theconcepts disclosed herein may apply to other types of switchable opticaldevices, including liquid crystal devices, suspended particle devices,and the like. For example, a liquid crystal device or a suspendedparticle device, instead of an electrochromic device, could beincorporated in any of the disclosed embodiments.

An insulated glass unit (IGU) is part of the transparent component of awindow. In the following description, an IGU may include twosubstantially transparent substrates, for example, two glass lites (alsoreferred to as panes), where at least one lite includes anelectrochromic device disposed thereon, and the lites have a spacerdisposed between them. One or more of the lites may itself be a laminatestructure of lites. An IGU is typically hermetically sealed, having aninterior region that is isolated from an exterior region including theambient environment. A window assembly may include an IGU, electricalconnectors for coupling the one or more electrochromic devices of theIGU to a window controller, and a frame that supports the IGU andrelated wiring.

Disclosed herein are various embodiments in which electrochromic windowsare incorporated in IGUs with spacers and connectors having improvedconfigurations. An electrochromic window includes a transparentsubstrate (e.g., a glass sheet or lite) on which is provided a thinelectrochromic device. Metal spacers conventionally employed in IGUs maynot work well with electrochromic windows due to, e.g., shorting issueswith the electrical components of the electrochromic device on one ormore lites of the window unit. Specifically, the IGUs disclosed hereingenerally have measures for avoiding electrical shorting between a metalspacer and conductive components of the electrochromic window, such asbus bars.

For example, electrochromic devices on glass lites use conductive wires,bus bars, or other connections that pass over, under or through a spacerused to form an IGU, for electrical communication to the electrochromicdevice. Spacers are often chosen, or required, to be a metal, and forsome IGUs, the glass lites may be compressed against the spacer. In someconfigurations, there are problematic issues created by compressing ametallic, conductive spacer against a conductor (e.g., the conductivewires, bus bars, or other connections) of the electrochromic device.Some conventional sealants may not suffice as insulators in suchconditions.

In order to orient the reader to the embodiments of IGUs disclosedherein, a brief discussion of electrochromic devices, edge deletion, andIGUs is provided. This initial discussion of electrochromic devices,edge deletion, and IGUs is provided for context only, and thesubsequently described embodiments of spacers are not limited to thespecific features and fabrication processes of this initial discussion.

Particular examples of electrochromic devices formed on substrates aredescribed with reference to FIGS. 1A-1C. FIG. 1A is a cross-sectionalrepresentation (along cut X-X as depicted in FIG. 1C) of anelectrochromic lite, 100, which is fabricated starting with a glasssheet, 105. FIG. 1B shows a different view from Y-Y as depicted in FIG.1C; i.e., FIG. 1B shows a view of electrochromic lite 100 from thebottom edge and in the plane of the paper (e.g., 90 degrees from thecross-sectional view shown in FIG. 1A). FIG. 1C shows a top-down view ofelectrochromic lite 100.

FIG. 1A shows an electrochromic lite after edge deletion (describedbelow), laser scribing, and bus bar attachment. Glass sheet 105 has adiffusion barrier, 110, and a first transparent conducting oxide (TCO)layer, 115, on the diffusion barrier. First TCO layer 115 is the firstof two conductive layers that form the electrodes of the electrochromicdevice fabricated on the glass sheet.

In some embodiments, the glass sheet as supplied may include thediffusion barrier layer as well as the first TCO layer. Thus, in someembodiments, an electrochromic stack, 120, and then a second TCO layer,125, may be formed in the fabrication of electrochromic lite 100. Theelectrochromic stack (also referred to as an electrochromic device) istypically a series of layers, e.g., an electrochromic layer, anelectrolyte layer, and an ion storage layer; however, in someembodiments electrochromic stack 120 is an electrochromic layer and anion storage layer with an interfacial region that acts as an electrolytelayer. Examples of electrochromic devices including such stacks aredescribed in U.S. patent application Ser. No. 12/772,055, filed Apr. 30,2010, titled “Electrochromic Devices,” and naming Wang et.al asinventors; the application is incorporated by reference in its entiretyherein. In some embodiments, electrochromic stack 120 and second TCOlayer 125 are fabricated in an integrated deposition system where glasssheet 105 does not leave the integrated deposition system at any timeduring fabrication of the stack. In some embodiments, first TCO layer115 is also formed using the integrated deposition system where glasssheet 105 does not leave the integrated deposition system duringdeposition of the stack/layers. In some embodiments, all of the layers(diffusion barrier 110, first TCO layer 115, electrochromic stack 120,and the second TCO layer 125) are deposited in the integrated depositionsystem where glass sheet 105 does not leave the integrated depositionsystem during deposition of the stack/layers.

After formation of the electrochromic device, edge deletion and laserscribing are performed. FIG. 1A depicts areas, 140, where portions ofthe electrochromic device have been removed from a perimeter regionsurrounding the laser scribe trenches, 130, 131, 132, and 133 (see alsoFIGS. 1B and 1C). The laser scribe trenches pass through the second TCOlayer and the electrochromic stack, but not through the first TCO. Thelaser scribe trenches are made to isolate portions of the electrochromicdevice, 135, 136, 137, and 138, from the operable electrochromic device.The isolated portions of the electrochromic device are portions thatwere potentially damaged during edge deletion and/or fabrication. If theedge deletion produces a clean cut edge to the device stack, e.g., usinglasers for the removal of material in the edge deletion, then theseisolation trenches may not be needed.

In some embodiments, laser scribe trenches 130, 132, and 133 passthrough the first TCO layer to aide in isolation of the device. Notethat laser scribe trench 131 does not pass through the first TCO layer;otherwise, it would cut off bus bar 2's electrical communication withthe first TCO layer and thus the electrochromic stack.

The laser or lasers used for the laser scribing are typically, but notnecessarily, pulse-type lasers, for example, including diode-pumpedsolid state lasers. For example, the laser scribing can be performedusing a suitable laser from IPG Photonics (Oxford, Mass.), or fromEkspla (Vilnius, Lithuania). Scribing can also be performedmechanically, for example, with a diamond tipped scribe. One of ordinaryskill in the art would appreciate that the laser scribing can beperformed at different depths and/or performed in a single processwhereby the laser cutting depth is varied, or not, during a continuous(or not) path around the perimeter of the electrochromic device. In someembodiments, the edge deletion is performed to the depth below the firstTCO layer. In some embodiments, a second laser scribe is performed toisolate a portion of the first TCO layer near the edge of the glasssheet from that toward the interior, as depicted in FIGS. 1A-C, forexample. In some embodiments, this scribe is at least along the edge ofelectrochromic lite 100 where bus bar 2 is applied to the first TCOlayer and is between bus bar 2 and the edge of electrochromic lite 100.

After laser scribing is complete, bus bars are attached. In FIGS. 1A-C,a non-penetrating bus bar 1 is applied to second TCO layer 125.Non-penetrating bus bar 2 is applied to an area where the device was notdeposited (for example, from a mask protecting first TCO layer 115 fromdevice deposition), in contact with first TCO layer 115 or, as depictedin FIG. 1A, where edge deletion was used to remove material down tofirst TCO layer 115. In this example, both bus bar 1 and bus bar 2 arenon-penetrating bus bars. A penetrating bus bar is one that is typicallypressed into and through the electrochromic stack to make contact withthe TCO layer at the bottom of the stack. In some embodiments, asoldering step, where a contact is soldered to a bus bar, may serve topenetrate the electrochromic stack and establish electrical contact to alower conducting layer. A non-penetrating bus bar is one that does notpenetrate into the electrochromic stack layers, but rather makeselectrical and physical contact on the surface of a conductive layer,for example, a TCO layer. Both types are suitable for use with theembodiments disclosed herein.

Edge deletion may be performed on a window where edge portions of anelectrochromic device are removed prior to integration of the windowinto the IGU. The edge portions may include, for example, regions of“roll off” where layers of an electrochromic stack that are normallyseparated contact one another due to non-uniformity in the layers nearthe edge of the electrochromic device.

Further, edge deletion may be employed for removal of one or moreelectrochromic device layers that would otherwise extend to underneaththe IGU. In some embodiments, isolation trenches are cut and theisolated portions of the electrochromic device on the perimeter of theelectrochromic lites are removed by edge deletion. The process ofperforming edge deletion is, in some embodiments, a mechanical processsuch as a grinding or sandblasting process. An abrasive wheel may beemployed for grinding. In some embodiments, edge deletion is done bylaser, where a laser is used to ablate electrochromic material from theperimeter of the electrochromic lite. The process may remove allelectrochromic device layers, including the underlying TCO layer, or itmay remove all electrochromic device layers except the bottom TCO layer.The latter case is appropriate when the edge deletion is used to providean exposed contact for a bus bar, which may be connected to the bottomTCO layer. In some embodiments, a laser scribe is used to isolate thatportion of the bottom TCO layer that extends to the edge of the glasssheet from that which is connected to the bus bar (sometimes referred toas a bus bar pad or contact pad) in order to avoid having a conductivepath to the electrochromic device from the edge of the glass sheet.

When edge deletion is employed, it can be performed before or after theelectrochromic lites are cut from the glass sheet (assuming that litesare cut from a larger glass sheet as part of the fabrication process).In some embodiments, edge deletion is performed in some edge areas priorto cutting the electrochromic lites and again after they are cut. Insome embodiments, all edge deletion is performed prior to cutting theelectrochromic lites. In embodiments employing edge deletion prior tocutting the electrochromic lites, portions of the electrochromic deviceon the glass sheet can be removed in anticipation of where the cuts (andthus edges) of the newly formed electrochromic lites will be. In mostfabrication processes, after edge deletion, bus bars are applied to theone or more electrochromic lites.

After the electrochromic devices with bus bars are fully assembled onthe glass sheets, IGUs are manufactured using the one or moreelectrochromic lites (e.g., refer to FIG. 3A and the associateddescription). Typically, an IGU is formed by placing a primary sealingspacer, which may include a gasket or sealing material (e.g., PVB(polyvinyl butyral), PIB (polyisobutylene), or other suitable elastomer)and a rigid spacer around the perimeter of the glass sheet. The primarysealing spacer may also be referred to as a primary sealant. In thedisclosed embodiments, the primary sealing spacer includes a metalspacer, or other rigid material spacer, and sealing material between themetal spacer and each glass lite. After the lites are joined to theprimary sealing spacer, a secondary seal may be formed around the outerperimeter of the primary sealing spacer. The secondary seal may be, forexample, a polymeric material that resists water and that addsstructural support to the IGU. Typically, but not necessarily, adesiccant is included in the IGU frame or spacer during assembly toabsorb any moisture and/or organic volatiles that may diffuse from thesealant materials. In some embodiments, the primary sealing spacersurrounds the bus bars and electrical leads to the bus bars extendthrough the seal. Typically, but not necessarily, the IGU is filled withinert gas such as argon. The completed IGU can be installed in, forexample, a frame or curtain wall and connected to a source ofelectricity and a controller to operate the electrochromic window.

As described above, after the bus bars are connected, the electrochromiclite is integrated into an IGU as shown in FIG. 2A, which includes, forexample, wiring for the bus bars and the like (wiring shown in FIG. 2B).In the embodiments described herein, both of the bus bars are inside theprimary seal of the finished IGU. FIG. 2A shows a cross-sectionalschematic diagram of the electrochromic window as described in relationto FIGS. 1A-C integrated into an IGU, 200. A spacer, 205, is used toseparate electrochromic lite 201 from a second lite, 210. Second lite210 in IGU 200 is a non-electrochromic lite, however, the embodimentsdisclosed herein are not so limited. For example, lite 210 can have anelectrochromic device thereon and/or one or more coatings such as low-Ecoatings and the like. Lite 201 can also be laminated glass, for examplewith glass lite 201 laminated to a reinforcing pane via a layer ofresin. Between spacer 205 and the first TCO layer of the electrochromiclite is a primary seal material, 215. This primary seal material is alsobetween spacer 205 and second glass lite 210. Around the perimeter ofspacer 205 is a secondary seal, 220. Bus bar wiring/leads traverse theseals for connection to controller. Secondary seal 220 may be muchthicker than depicted. These seals aid in keeping moisture out of aninterior space, 202, of the IGU. They also serve to prevent argon orother gas in the interior of the IGU from escaping.

The electrochromic window may be controlled to provide a desired opticalwindow state. Details regarding voltages and algorithms used for drivingan optical state transition for an electrochromic device may be found inU.S. patent application Ser. No. 13/049,623, titled “CONTROLLINGTRANSITIONS IN OPTICALLY SWITCHABLE DEVICES,” filed Mar. 16, 2011, whichis herein incorporated by reference.

Along with voltage algorithms, there is associated wiring andconnections for the electrochromic device being powered. FIG. 2B showsan example of a cross-sectional schematic of an electrochromic device,250. Electrochromic device 250 includes a substrate, 255. The substratemay be transparent and may be made of, for example, glass. A firsttransparent conducting oxide (TCO) layer, 260, is on substrate 255, withfirst TCO layer 260 being the first of two conductive layers used toform the electrodes of electrochromic device 250. Electrochromic stack265 may include (i) an electrochromic (EC) layer, (ii) an ion-conducting(IC) layer, and (iii) a counter electrode (CE) layer to form a stack inwhich the IC layer separates the EC layer and the CE layer.Electrochromic stack 265 is sandwiched between first TCO layer 260 and asecond TCO layer, 270, TCO layer 270 being the second of two conductivelayers used to form the electrodes of electrochromic device 250. FirstTCO layer 260 is in contact with a first bus bar, 280, and second TCOlayer 270 is in contact with a second bus bar, 275. Wires, 281 and 282,are connected to bus bars 280 and 275, respectively, and form a wireassembly (not shown) which terminates in a connector, 285. Wires ofanother connector, 290, may be connected to a controller that is capableof effecting a transition of electrochromic device 250, e.g., from afirst optical state to a second optical state. Connectors 285 and 290may be coupled, such that the controller may drive the optical statetransition for electrochromic device 250.

Further details regarding electrochromic devices may be found in U.S.patent application Ser. No. 12/645,111, titled “FABRICATION OF LOWDEFECTIVITY ELECTROCHROMIC DEVICES,” filed Dec. 22, 2009. Furtherdetails regarding electrochromic devices may also be found in U.S. Pat.No. 8,432,603, filed Dec. 22, 2009, U.S. Pat. No. 8,300,298, filed Apr.30, 2010, U.S. patent application Ser. No. 12/814,277 filed Jun. 11,2010, and U.S. patent application Ser. No. 12/814,279 filed Jun. 11,2010, each titled “ELECTROCHROMIC DEVICES;” each of the aforementionedare herein incorporated by reference.

In accordance with voltage algorithms and associated wiring andconnections for powering an electrochromic device, there are alsoaspects of how the wired EC glazing is incorporated into an IGU and howthe IGU is incorporated into, e.g., a frame. FIG. 3A shows examples ofthe operations for fabricating an insulated glass unit, 325, includingan electrochromic pane, 305, and incorporating the insulated glass unitinto a frame, 327. Electrochromic pane 305 has an electrochromic device(not shown, but for example on surface A) and bus bars, 310, whichprovide power to the electrochromic device. Electrochromic pane 305 ismatched with another glass pane, 315. The electrochromic pane mayinclude, for example, an electrochromic device similar to theelectrochromic device shown in FIGS. 2A and 2B, as described above. Insome embodiments, the electrochromic device is solid state andinorganic.

During fabrication of IGU 325, a separator, 320 is sandwiched in betweenand registered with glass panes 305 and 315. IGU 325 has an associatedinterior space defined by the faces of the glass panes in contact withseparator 320 and the interior surfaces of the separator. Separator 320may be a sealing separator, that is, the separator may include a spacerand sealing material (primary seal) between the spacer and each glasspane where the glass panes contact the separator. A sealing separatortogether with the primary seal may seal, e.g., hermetically, theinterior volume enclosed by glass panes 305 and 315 and separator 320and protect the interior volume from moisture and the like. Once glasspanes 305 and 315 are coupled to separator 320, a secondary seal may beapplied around the perimeter edges of IGU 325 in order to impart furthersealing from the ambient environment, as well as further structuralrigidity to IGU 325. The secondary seal may be a silicone based sealant,for example.

IGU 325 may be wired to a window controller, 350, via a wire assembly,330. Wire assembly 330 includes wires electrically coupled to bus bars310 and may include other wires for sensors or for other components ofIGU 325. Insulated wires in a wire assembly may be braided and have aninsulated cover over all of the wires, such that the multiple wires forma single cord or line. A wire assembly may also be referred to as a“pig-tail.” IGU 325 may be mounted in frame 327 to create a windowassembly, 335. Window assembly 335 is connected, via wire assembly 330,to window controller, 350. Window controller 350 may also be connectedto one or more sensors in frame 327 with one or more communicationlines, 345. During fabrication of IGU 325, care must be taken, e.g., dueto the fact that glass panes may be fragile but also because wireassembly 330 extends beyond the IGU glass panes and may be damaged.

FIG. 3B depicts an example of a window assembly, 335, including frame340. The viewable area of the window assembly is indicated on thefigure, inside the perimeter of frame 340 (using a heavy black line). Asindicated by dotted lines, inside frame 340 is IGU 325 which includestwo glass lites separated by sealing spacer 320, shaded in gray.

In some embodiments, an edge bumper is employed to protect the edges ofthe glass after incorporation in the IGU. This protection allows the IGUto be safely transported from manufacturer to installation, for example.In some embodiments, the protective bumper is a U-channel cap which fitsover the glass edges around the perimeter of the IGU. It may be madefrom an elastomeric or plastic material. In some embodiments, the edgebumper is a vinyl cap.

FIG. 4 is a facing or front view of an IGU, 400, which includeselectrochromic lite 305 as depicted in FIG. 3A. Electrochromic lite 305has bus bars 310 fabricated on an electrochromic device (not depicted).FIG. 4 shows the relative configurations of the spacer, theelectrochromic lite, the wiring, and so forth. Spacer 320 surrounds busbars 310 and overlays leads to the bus bars. In some embodiments, thebus bar leads may be a conductive ink. Wiring, 405, connects to bus bars310 via the bus bar leads. Wiring 405 further occupies at least aportion of the secondary seal area and then passes out of IGU 400. Insome embodiments, wiring 405 may be insulated (i.e., the wiring may havea conductive metal core covered with an insulating material, forexample).

Because the spacer in a conventional IGU is made from a metal, such as asteel hollow bar or a stainless steel hollow bar, for example, it canpossibly short out one or more features contained in an electrochromicdevice employed in an electrochromic window. Using IGU 325 (see FIG. 3A)as an example, lite 315 is pressed together with electrochromic lite 305with spacer 320 and a primary sealant material there between. With thebus bar leads extending under spacer 320, there is a chance of shortingbetween the bus bar leads and the spacer.

In some embodiments, rather than bus bar leads traversing the area wherethe spacer presses against the primary sealant material, wires 405 maytraverse the area. However, the compression used to assemble an IGU maycompromise the integrity of insulation on wires 405. In someembodiments, wires 405 may be thin, flat wires (e.g., braided wirecabling, ribbon cable, circuit-board type flat electrical connections)with insulation over the wires. In some embodiments, the wires runbetween the spacer and the lite, rather than leads as depicted in FIG.4. Even if thin, flat wires are used, there still may be issues withshorting.

FIG. 4 further shows examples of three modes of potential shorting ofthe electrochromic device to the spacer and consequent failure of theelectrochromic device. Reference X illustrates a potential short betweenthe bus bar and the spacer at a “crossover point,” e.g., the bus barlead. The crossover point can be understood as the electrical connectionbetween the bus bar of the electrochromic device and an externalconnection to the bus bar from outside the interior space of the IGU.Typically, the external connection provides power from a voltage orother power source to the bus bar. The bus bar provides power to one ofthe two sheet electrodes of the electrochromic device. In the aboveembodiments, the sheet electrodes are typically transparent conductiveoxides (TCOs), such as indium tin oxide (ITO) or TEC (a fluorinated tinoxide conductive layer provided on glass lites marketed under thetrademark TEC Glass™ by Pilkington). The contact between the bus barlead and the spacer shown as reference X is a region where the bus barlead (or a wire) extends across the spacer from the interior space ofthe IGU to the secondary seal area. The bus bar lead, which is anextension of the bus bar, is sometimes referred to as a “bus bar exit.”Whichever wiring configuration is used, there is a potential forshorting with a conductive spacer. As will be described in more detailbelow, one mode of addressing this potential problem of an electricalshort between the spacer and the bus bar lead is by creating a smallnotch or “mouse hole” in the underside side of the spacer that contactsthe lite in order to allow room for the bus bar lead (or wire) to passbetween the lite and the spacer without contacting the spacer.

A second potential short or failure area depicted in FIG. 4 isillustrated by reference Y. In area Y, between the bus bar and thespacer, it is possible that the bus bar itself may contact theconductive spacer. Because the bus bar is a relatively long structure,oriented along one edge of the window, the bus bar could contact acorresponding point on the metal spacer anywhere along the length of thebus bar. Typically the bus bar is situated as close as possible to thespacer without touching it, in order to maximize viewable area of thewindow. Because of the tight tolerances employed in manufacturing anelectrochromic device, it is possible that there will be some minormisalignment of the bus bar and/or the spacer resulting in contact inthe area indicated by Y. The bus bar itself typically resides on aninactive area of the electrochromic device, for example, behind a laserscribe line, and the bus bar material used is often light in color. Withthis also in mind, the bus bar is typically placed very close to theedge of the window at the edge of the electrochromic device. As aconsequence, it is typically placed very close to the spacer.

The third mode of potential shorting and failure is illustrated byreference Z. As shown, a contact can occur between the spacer and someamount of the transparent conductive electrode employed in theelectrochromic device. While it is typical to remove some or all of theelectrochromic device stack, for example, in an edge delete process, itis not uncommon to have some small amount of an underlying conductivefilm such as ITO or TEC remain near the edge of the device on thewindow. As described above, the primary sealant, such as PM or PVB,typically separates the metal spacer bar from the glass lite with thetransparent conductive electrode. However, the primary sealant candeform under pressure and it is not uncommon for the sealant to besqueezed out of the seal area over time. As a consequence, there is asignificant risk that the spacer will electrically contact some of thetransparent conductive electrode and cause a short.

It should be understood that the design placement of the bus bar, theconnectors/leads, the location of the conductive electrode layers, etc.,are specified with very tight tolerances, e.g., on the order of about afew millimeters or less. It has been found in practice that thespecification may not be met. Therefore, each of the three depictedmodes of shorting failure represents a significant design challenge. Thediscussion herein describes certain embodiments that address one or moreof these potential modes of failure. One of ordinary skill in the artwould appreciate that, where useful, combinations of these embodimentsare contemplated as individual embodiments herein. Certain embodimentsare described in terms of an IGU; however, one embodiment is a spacer asdescribed herein, or a sub-assembly of an IGU described herein.

FIG. 5A shows an example of a cross section, 500, of an edge region ofan IGU where the spacer of the IGU and the bus bar reside. Asillustrated, a spacer, 510, is sandwiched between two sheets of glassnear the edge of the IGU. In a typical design, the glass interfacesdirectly with a primary seal material, 515, (e.g., a thin elastomericlayer, such as PIB or PVB), which is in direct contact with spacer 510.In some embodiments, spacer 510 may be metal spacer, such as a steelspacer or a stainless steel spacer, for example. This three-partinterface (i.e., glass/primary seal material/spacer) exists on both atop piece of glass and a bottom piece of glass. Spacer 510 may have ahollow structure, as depicted in FIG. 5A. In some embodiments, thespacer may have a substantially rectangular cross section. At a minimum,spacers described herein have at least two surfaces, each substantiallyparallel to the lites of the IGU in which they are to be incorporated.The remaining cross section, e.g., surfaces of the spacer that face theinterior space of the IGU and the exterior, secondary seal area, mayhave any number of contours, i.e., they need not be flat, but may be. Inthe example depicted in FIG. 5A, spacer 510 has two surfaces on eachface that forms the primary seal, which are substantially parallel tothe glass lites of the IGU (a raised surface on the left hand side ofthe spacer 510 and a depressed surface (notch 501) on the right handside of the spacer 510). In some embodiments, the top and bottom outercorners of the spacer are beveled and/or rounded to produce a shallowerangle in these areas. Rounding, beveling, or smoothing may be includedto ensure there are no sharp edges that might enhance electricalshorting. An electrochromic device stack, 505, is fabricated on thelower glass lite, as depicted. A bus bar, 520, is located onelectrochromic device stack 505 in order to make electrical contact withone of the electrodes of the device. In this example, bus bar 520 isbetween spacer 510 and the lower glass lite. This is accomplished byconfiguring one of the aforementioned surfaces below (see top surface ofspacer 510) or above (see bottom surface of spacer 510) the othersurface on the face of the spacer that forms the primary seal with theglass surface. This configuration of surfaces forms “notch” 501; seefurther description below. Primary seal material 515 serves as aninsulating layer between bus bar 520 and spacer 510.

There are two primary distinctions between a normal spacer design andspacer 510 shown in FIG. 5A. First, spacer 510 is relatively thicker(wider) in the direction parallel to the glass sheet (i.e., a largerfootprint as would be typical from the view depicted in FIG. 3B, forexample). A conventional metal spacer is approximately 6 millimeters inwidth. Spacer 510 is about two times to about two and one half times(about 2× to about 2.5×) that width. For example, spacer 510 may beabout 10 millimeters to about 15 millimeters wide, about 13 millimetersto about 17 millimeters wide, or about 11 millimeters wide. Thisadditional width may provide a greater margin of error in a sealingoperation compared to a conventional spacer.

The second significant distinction of spacer 510 from a conventionalspacer is in the use of recesses or notches 501 on the upper and lowerinner corners of spacer 510. In some embodiments, a spacer may includetwo notches, and in some embodiments, the spacer may include one notch.Two notches, e.g., as depicted in FIG. 5A, may be used for an IGUcontaining two electrochromic lites, or may be useful in fabricatingIGUs with only one electrochromic light. When using a spacer with twonotches in an IGU containing one electrochromic lite, there is no needfor special placement of a single notch toward the electrochromic lite.In some embodiments, a recess or notch may extend from a corner of oneside of the rectangular cross section of the spacer to a point along theone side of the rectangular cross section of the spacer. At least onenotch provides an area for covering the bus bar formed on the glasssurface and/or covering the bus bar formed on electrochromic devicestack 505 formed on the glass surface. In some embodiments, the bus baris about 2 millimeters to about 3 millimeters in width and about 0.01millimeters to about 0.1 millimeter in height (thickness). The bus barlength depends on the window size. In some embodiments, a bus bar mayhave a length about the length of the electrochromic device. The addedwidth, along with the “notched” profile of spacer 510 that accommodatesthe bus bar, creates a region of “encapsulation” whereby the bus bar isunlikely to contact the spacer at any point along the length of the busbar, but is encapsulated in the primary sealant.

In some embodiments, the portion of the spacer's face that does notinclude the notch (i.e., the outer portion of the spacer) isapproximately the same width as a normal spacer employed innon-electrochromic IGU applications. As depicted in FIG. 5A, bus bar 520is entirely covered by the spacer 510. As a consequence, the bus bar isnot visible to a user of the window.

In FIG. 5A, electrochromic device stack 505 extends underneath bus bar520 and partially into the region formed by notch 501 in spacer 510. Asnoted above, an electrochromic device stack typically includes aconductive electrode layer such as ITO or TEC. Electrochromic devicestack 505 may be entirely removed from the edge of the glass surface byan edge deletion process, described above. However, the removal by edgedeletion may not extend entirely up to the edge of the bus bar, as thiswould be unacceptable given normal process tolerances. Therefore,electrochromic device stack 505 may extend just slightly beyond bus bar520, e.g., while still residing in notch 501.

Spacer 510, which is wider than conventional spacers, as well as notches501 in spacer 510, provide additional space for primary seal material515 (e.g., PIB). This feature, along with the notch or notches on thetop and/or bottom inside edges of the spacer, give spacer 510 variousadvantages that are particular to electrochromic devices incorporated inIGUs. For example, a wider primary seal area provides better containmentof argon or other gas within the IGU interior as well as protection ofthe IGU from moisture and other gasses in the ambient environment. Thesealing of the IGU secondary seal also may be improved and may providebetter structural integrity than a conventional IGU design.Additionally, the IGU may color all the way to the edge defined by theinterior perimeter of the spacer. With the bus bars hidden underneaththe notch in the spacer, there will be no bright sight lines createdeither by the inactive area where the bus bar is placed or by therelatively lightly colored material used to fabricate the bus bar.

Still further, the disclosed embodiment will satisfy industryexpectations for an IGU that contains a primary seal having aglass/primary seal material (e.g., PIB)/metal spacer construction.Additionally, because the electrochromic device may employ an edgedeletion down to the level of the glass (or the diffusion barrier) andfrom the glass edge to an area where a notch of the bus bar will form aportion of the primary seal and thus provide more space between the busbar and spacer, the likelihood of shorting between the electrochromicdevice electrode and the spacer is greatly reduced. FIG. 5B showscross-sections of other spacers, 540-575, in accord with embodimentsdescribed herein, each spacer having at least one notch 501.

As noted, embodiments described herein, including notched embodiments,may employ a channel or “mouse hole” under an edge of the spacer where alead or a connector to the bus bar may run to allow connection to anoutside power source (described further herein). One embodiment is thespacer as described in relation to FIGS. 5A and 5B including a channelon one or both faces of the spacer that form the primary seal with thelite or lites. As also noted, the bus bar lead is typically orientedsubstantially perpendicular to the line of the bus bar itself. It istypically made from the same material as the bus bar (e.g., silver,conductive ink, or other highly conductive material). The channel ormouse hole may be formed in a metal spacer, e.g., stainless steel, or bepart of a connector key that joins two ends of a slotted, open, spacer.This is described in more detail below.

FIG. 6 shows two embodiments of connector keys. A connector key istypically used to join two ends of a spacer. As noted above, a spacermay be made from hollow metal rectangular pieces. One or more of thesepieces are bent into an overall rectangular-shaped piece that forms thespacer. This rectangular-shaped spacer is sized and shaped to mate withthe perimeter of the glass used to form an IGU. Two ends of the one ormore pieces of tubular spacer material are joined by a connector key.For example, an end of the tubular spacer material may slide over aportion of a connector key, and the other end of the tubular spacermaterial may slide over another portion of the connector key.Alternatively, as depicted in FIG. 6, the ends of the metal spacer slideinto the connector key.

Each of the connector keys in FIG. 6 has been modified to accommodate abus bar lead. In some embodiments, a metal spacer and a primary sealmaterial form a barrier between an interior region of the windowassembly and an exterior region of the window assembly. A lead or a wirepasses from an electrode of an optically switchable device on theinterior region of the window assembly, under a connector key, and tothe exterior region of the window assembly. The connector key is not inelectrical communication with the lead or the wire.

In embodiment 600, a connector key, 605, joins two ends, 620, of thespacer. In some embodiments, the spacer may be a metal spacer, such as asteel spacer or a stainless steel spacer, for example. In someembodiments, the spacer may have a substantially rectangular crosssection. In some embodiments, the spacer may be hollow. The two ends ofthe spacer, 607, slide into the respective ends of connector key 605.The connector key and spacer are configured so that when joined, thesurfaces that are to come into contact with the glass are substantiallyco-planar. Connector key 605 has a middle section that is made from ametal, particularly a crimpable metal, such as steel or stainless steel,for example. The bottom portion of the middle region of connector key605 is made from this crimpable metal and is in fact crimped to producethe channel 609 or mouse hole under which the bus bar lead passes. Ofcourse, connector key 605 could be cast or machined to achieve the sameresult, but stamped or crimped metal is more economical.

In some embodiments, instead of a bus bar lead passing under channel609, wiring for an electrode may pass under channel 609. For example, insome embodiments, the wire may be thinner than the thickness (i.e.,height) of the channel. In some embodiments, when a thin wire is used,the thickness (i.e., height) of the channel may be reduced.

In embodiment 610, a connector key, 615, joins two ends, 620, of thespacer. The two ends of the spacer, 617, slide into the ends ofconnector key 615. Connector key 615 is an electrically non-conductiveor insulating material (e.g., a plastic). Connector key 615 may or maynot have a channel or mouse hole cut into it. Typically, such a channelwill be unnecessary because connector key 615 is a non-conductive orinsulating material, thereby eliminating the possibility of a shortbetween the connector key and the bus bar lead. Thus, the connector keyand the lead will not be in electrical communication.

It should be noted that the connector key normally sits at a randomlocation in the spacer. This is because the tubular metal pieces used tomake the spacer typically come in standard or fixed lengths. Theselengths may be used to construct a rectangular spacer of effectivelyarbitrary size, as dictated by the size of the window and the associatedIGU. In accordance with the embodiments shown FIG. 6, the spacer may beconstructed in a manner in which the connector key lines up with atleast one of the bus bar leads. In some embodiments, the spacer isdesigned so that two separate connector keys are specifically aligned tocoincide with the position of the two bus bar leads at opposite sides ofthe electrochromic device. In some embodiments, one of the connectorkeys is forced into alignment on the spacer with the bus bar lead. Insuch embodiments, the opposite bus bar lead may pass through a channelcreated in the body of the tubular metal used to make the spacer. Such achannel may be created by, e.g., forming a dent or a crimp in thetubular metal piece at a location coinciding with the bus bar lead.

In some other embodiments, the spacer is constructed using conventionalconnector keys. The spacer may then be dented or crimped at thelocations where the bus bar lead passes.

FIG. 7 shows an example of a detailed cross-sectional view of a crimpedconnector key aligned on a glass sheet with an electrochromic devicefabricated thereon. Particularly, the detailed view, 700, shows achannel (mouse hole), 705, in the middle portion of a connector key,710, where a bus bar lead, 715, on a glass lite, 720, passes through thechannel. Various sample dimensions are provided in FIG. 7. It should beunderstood that these are only examples and that many other dimensionsmay be appropriate. In some embodiments, bus bar lead 715 may have aheight, 725, of about 0.05 millimeters to about 0.1 millimeters. In someembodiments, channel 705 may have a height, 730, of about 0.1millimeters to about 1 millimeter. In some embodiments, channel 705 mayhave a width in connector key 710 of about 4.5 millimeters to about 10millimeters. In some embodiments, a clearance, 735, that may be desiredon either side of bus bar 715 may be between about 1.5 and about 2.5millimeters.

A crimping process that may be used to form a crimped metal connectorkey may have tolerances associated with the process. Therefore, thechannel formed in a connector key may be specified to be somewhat largerthan what is desired to account for the tolerances in the process.

In some embodiments, the channel for the bus bar lead is located as inthe embodiment described with respect to FIGS. 6 and 7, but need onlypenetrate part way under the spacer because the bus bar resides midwayunderneath the spacer. In some embodiments, the bus bar lead channelresides on an outside edge of the spacer or on an outside edge of acorner of the spacer.

FIG. 8 is a schematic diagram of an insulated glass unit, 800, includingan electrochromic pane, 805, and an associated wire assembly, 830. IGU800 includes electrochromic pane 805 which includes bus bars, 815, whichare in electrical communication with an EC device, 817 (for an exemplarycross-section see FIG. 2A). Electrochromic pane 805 is matched withanother pane (not shown) and attached to the other pane with aseparator, 820 (indicated by the dotted lines). The area of EC pane 805outside of separator 820 is a secondary sealing area, while EC devicelies within the perimeter of separator 820 (which forms the primary sealagainst the glass panes of the IGU). In the assembled IGU, the secondarysealing area is typically filled with a sealing compound to form asecondary seal. Wires, 822 and 823, are connected to bus bars 815 andextend through IGU 800 from bus bars 815, through or under spacer 820,and within the secondary seal to a first connector, 825. Wires 822 and823 may be positioned such that they do not appear in the viewableregion of the panes. For example, the wires may be enclosed in thesealing separator or the secondary seal as depicted. In someembodiments, and as depicted, first connector 825 may be housedsubstantially within the secondary seal. For example, first connector825 may be surrounded by the secondary sealant on all sides except forthe face of first connector 825 having two pads, 827. The firstconnector may be housed substantially within the secondary seal indifferent manners. For example, in some embodiments, the first connectormay be housed substantially within the secondary seal and be recessedrelative to the edges of the glass panes. In some embodiments, the firstconnector may be housed substantially within the secondary seal andprotrude beyond the edges of the glass panes. In other embodiments,first connector 825 may itself form part of the secondary seal, e.g., bysandwiching between the glass panes with sealant disposed between itselfand the glass panes.

As noted above, first connector 825 includes two pads 827. The two padsare exposed and provide electrical contact to wires 822 and 823. In thisexample, first connector 825 further includes a ferromagnetic element,829. Wire assembly 830 includes a second connector, 835, configured tomate with and provide electrical communication with pads 827. Secondconnector 835 includes a surface having two pads, 840, that provideelectrical contact to wires, 845, of the wire assembly. Second connector835 further includes a ferromagnetic element, 850, configured toregister and mate with ferromagnetic element 829 of the first connector.

Pads 840 of second connector 835 are configured or shaped for mechanicaland electrical contact with pads 827 of first connector 825. Further, atleast one of ferromagnetic elements 829 or 850 of first connector 825 orsecond connector 835, respectively, may be magnetized. With at least oneof ferromagnetic elements 829 or 850 being magnetized, first connector825 and second connector 835 may magnetically engage one another andprovide electrical communication between their respective pads. Whenboth ferromagnetic elements are magnetized, their polarity is oppositeso as not to repel each other when registered. A distal end (not shown)of the wire assembly 830 may include terminals, sometimes provided in aplug or socket, that allow the wire assembly to be connected to a windowcontroller. In one embodiment, a distal end of wire assembly 830includes a floating connector.

In one embodiment, rather than a pad to pad contact (e.g., 827 to 840 asin FIG. 8) for the first and second connectors, a pad to spring-type pinconfiguration is used. That is, one connector has a pad electricalconnection and the other connector has a corresponding spring-type pin,or “pogo pin”; the spring-type pin engages with the pad of the otherconnector in order to make the electrical connection. In one embodiment,where ferromagnetic elements are also included, the magnetic attractionbetween the ferromagnetic elements of the first and second connectors issufficiently strong so as to at least partially compress the springmechanism of the pogo pin so as to make a good electrical connectionwhen engaged. In one embodiment, the pads and corresponding pogo pinsare themselves the ferromagnetic elements.

In some embodiments, first connector 825, second connector 835, or theterminals or connector at the distal end of the wire assembly (e.g. afloating connector) may include a memory device and/or an integratedcircuit device. The memory device and/or integrated circuit device maystore information for identifying and/or controlling electrochromic pane805 in IGU 800. For example, the device may contain a voltage andcurrent algorithm or voltage and current operating instructions fortransitioning electrochromic pane 805 from a colored stated to ableached state or vice versa. The algorithm or operating instructionsmay be specified for the size, shape, and thickness of electrochromicpane 805, for example. As another example, the device may containinformation that identifies the shape or size of electrochromic pane 805to a window controller such that electrochromic pane 805 may operate inan effective manner. As yet another example, the device may containinformation specifying a maximum electric signal and a minimum electricsignal that may be applied to electrochromic pane 805 by a windowcontroller. Specifying maximum and minimum electric signals that may beapplied to the electrochromic pane may help in preventing damage to theelectrochromic pane.

In another example, the memory and/or integrated circuit device maycontain cycling data for the EC device to which it is connected. Incertain embodiments, the memory and/or integrated circuit deviceincludes part of the control circuitry for the one or more EC devices ofthe IGU. In one embodiment, individually, the memory and/or integratedcircuit device may contain information and/or logic to allowidentification of the EC device architecture, glazing size, etc., asdescribed above, e.g., during a testing or initial programming phasewhen in communication with a controller and/or programming device. Inone embodiment, collectively, the memory and/or integrated circuitdevice may include at least part of the controller function of the IGUfor an external device intended as a control interface of the installedIGU.

Further, in embodiments in which first connector 825 includes the memorydevice and/or the integrated circuit device, damage to theelectrochromic pane may be prevented because the device is part of IGU800. Having the maximum and minimum electric signals that may be appliedto electrochromic pane 805 stored on a device included in firstconnector 825 means that this information will always be associated withIGU 800. In one example, a wiring assembly as described herein includesfive wires and associated contacts; two of the wires are for deliveringpower to the electrodes of an EC device, and the remaining three wiresare for data communication to the memory and/or integrated circuitdevice.

Wire assembly 830 described with respect to FIG. 8 may be easilyattachable to, and detachable from, IGU 800. Wire assembly 830 also mayaid in the fabrication and handling of an IGU because wire assembly 830is not permanently attached to the IGU and will therefore not interferewith any fabrication processes. This may lower the manufacturing costsfor an IGU. Further, as noted above, in some IGUs that include wireassemblies that are permanently attached to the IGU, if the wireassembly becomes damaged and/or separated from the IGU, the IGU may needto be disassembled to reconnect the wire assembly or the IGU may need tobe replaced. With a detachable wire assembly, an IGU may be installedand then the wire assembly attached, possibly precluding any damage tothe wire assembly. If a wire assembly is damaged, it can also be easilyreplaced because it is modular.

Additionally, the detachable wire assembly allows for the replacement orthe upgrade of the wire assembly during the installed life of theassociated IGU. For example, if the wire assembly includes a memory chipand/or a controller chip that becomes obsolete or otherwise needsreplacing, a new version of the assembly with a new chip can beinstalled without interfering with the physical structure of the IGU towhich it is to be associated. Further, different buildings may employdifferent controllers and/or connectors that each require their ownspecial wire assembly connector (each of which, for example, may have adistinct mechanical connector design, electrical requirements, logiccharacteristics, etc.). Additionally, if a wire assembly wears out orbecomes damaged during the installed life of the IGU, the wire assemblycan be replaced without replacing the entire IGU.

In certain embodiments, each of the first and second connectors includesat least two ferromagnetic elements. In a specific embodiment, each ofthe first and second connectors includes two ferromagnetic elements. A“double” magnetic contact allows for more secure connections. Magnetssuch as neodymium based magnets, e.g., comprising Nd₂Fe₁₄B, are wellsuited for this purpose because of their relatively strong magneticfields as compared to their size. As described above, the twoferromagnetic elements may be part of the electrical pads, or not. Inone embodiment, the two ferromagnetic elements in each of the first andthe second connectors are themselves magnets, where the poles of themagnets of each of the first and second connectors that are proximatewhen the connectors are registered, are opposite so that the respectivemagnets in each of the first and second connectors attract each other.

When installing an IGU in some framing systems, e.g., a window unit orcurtain wall where multiple IGUs are to be installed in proximity, it isuseful to have flexibility in where the electrical connection is made toeach IGU. This is especially true since typically the EC glazing of theIGUs is always placed on the outside of the installation, facing theexternal environment of the installation. Given this configuration,having the connectors in the same position within the secondary seal ofthe IGUs of the installation requires much more wiring to thecontroller. However, for example, if the electrical connectors in theIGUs (as described herein) can be positioned more proximate to eachother, then less wiring is needed from the IGU to the framing system inwhich the IGUs are installed. Thus, in some embodiments, IGU 800 mayinclude more than one first connector 825, that is, redundant connectorsare installed. For example, an IGU 800 might include not only a firstconnector 825 at the upper right hand side, but also another connectorat the lower left hand side or at the lower right hand side or the upperleft hand side or in the top or bottom portion of the IGU. In thisexample, the connectors are all within the secondary seal. The exactposition on each edge is not critical; the key is having more than oneconnector that feeds the same EC device so that when installing the IGU,there is flexibility in where to attach the external connector to theIGU. When an IGU having multiple connectors is mounted in a frameholding 2, 4, 6, or more similar IGUs, for example, having multiplefirst connectors included within each IGU, allows for more convenientrouting of the wires (e.g., wires 845 as in FIG. 8 associated with eachwire assembly 830) in the frame due to the flexibility of havingmultiple redundant first connectors to which the second connector may becoupled. In one embodiment, the IGU has two first connectors, in anotherembodiment three first connectors, in yet another embodiment four firstconnectors. In certain embodiments there may be five or six firstconnectors. Although the number of connectors may impact productioncosts, this factor may be more than compensated for by the higher degreeof flexibility in installation, e.g., in an expensive and sophisticatedcurtain wall installation where volume to accommodate wiring is oftenlimited and installing multiple first connectors during fabrication isrelatively easy.

In some embodiments, the IGU 800, may include two electrochromic panes.In these embodiments, the first connector may include four pads (orcorresponding pad to pin contacts) to provide contacts to the bus barsof each of the electrochromic panes (i.e., each electrochromic panewould include at least two bus bars). Additional pads for control andcommunication with the electrochromic device and/or onboard controllermay also be included, e.g., four pads for bus bar wiring and threeadditional pads for communication purposes. Likewise, second connector835 would include four pads to provide electrical contact to wires ofthe wire assembly. In other embodiments, each EC pane may have its ownfirst connector, or two or more redundant first connectors. Furtherdescription of an IGU that includes two or more electrochromic panes isgiven in U.S. Pat. No. 8,270,059, titled “MULTI-PANE ELECTROCHROMICWINDOWS,” filed Aug. 5, 2010, which is herein incorporated by reference.

FIG. 9 shows a schematic diagram of an insulated glass unit including anelectrochromic pane and an associated ribbon cable. The IGU 900 includesan electrochromic pane, 905, having bus bars, 915, which are inelectrical communication with an EC device, 917 (for an exemplarycross-section see FIG. 2A). Electrochromic pane 905 is matched withanother pane (not shown) and attached to the other pane with aseparator, 920 (indicated by the dotted lines). Outside of separator 920is a secondary sealing area. Wires 922 and 923 are connected to bus bars915 and extend through IGU 900 to a connector, 902. Connector 902 iscapable of being connected to a ribbon cable, 905. Ribbon cable 905 maybe connected to a window controller, 910. In some embodiments, theribbon cable may be a cable with many conducting wires running parallelto each other on the same plane. The ends of the ribbon cable mayinclude connectors for connecting to connector 902 and to windowcontroller 910.

In some embodiments, connector 902 may be similar to connector 825 ofFIG. 8 (i.e., connector 902 may include one or more ferromagneticelements) and ribbon cable 905 also may include one or moreferromagnetic elements for engaging connector 902 with ribbon cable 905.Other mechanisms also may be used to engage connector 902 with ribboncable 905.

In some embodiments, connector 902 may include a memory device and/or anintegrated circuit device. Ribbon cable 905 may include more wires orelectrically conductive paths than the two paths needed to electricallyconnect to bus bars 915 of electrochromic pane 905 so that the windowcontroller can communicate with the memory device and/or the integratedcircuit device. In some embodiments, the ribbon cable may haveelectrically conductive paths for controlling more than oneelectrochromic pane, as described below. Ribbon cables have advantagesincluding the capability of having multiple parallel wires for carryingpower, communication signals etc., in a thin, flexible format.

In some embodiments, IGU 900 includes two or more electrochromic panes.Connector 902 may be capable of providing electrical contact to the busbars of each of the electrochromic panes (i.e., each electrochromic panewould include at least two bus bars). Thus, in the example of an IGUhaving two electrochromic panes, the ribbon cable may include fourconducting wires running parallel to each other on the same plane forpowering the electrochromic panes.

As described above, where a connector is configured within an IGU may beimportant when considering where to attach wiring connectors to the IGU.Flexibility in attaching wiring assemblies to an IGU can significantlyreduce wiring complexity and length, and thus save considerable time andmoney, both for fabricators and installers. One embodiment is anelectrical connection system including a track, the track including twoor more rails that provide electrical communication, via wiring and busbars, to the electrodes of an EC device of the IGU. The track is, e.g.,embedded in the secondary sealing area of the IGU. An associatedconnector engages the rails and thereby makes electrical connection tothe rails. A non-limiting example of the track described above isdescribed in relation to FIGS. 10A and 10B.

FIGS. 10A and 10B depict aspects of an insulated glass unit, 1000,including a track, 1025, and an associated connector, 1045. In thisexample, track 1025 is also a spacer that may serve as both a secondarysealing element and an electrical connector for an electrochromic paneof the IGU, although the sealing function is not necessary. FIG. 10A isa schematic diagram of IGU 1000 including an electrochromic pane, 1010.Electrochromic pane 1010 includes bus bars, 1015. Electrochromic pane1010 is matched with another pane (not shown) and together the panessandwich a separator, 1020, with a primary seal being formed betweenseparator 1020 and the inside surfaces of the panes along with anadhesive. In this example, track 1025 is used to form a secondary seal,similar to the primary seal formed between the glass panes and separator1020, with an adhesive between the inner surfaces of the glass panes andtrack 1025. Thus, in this example, the primary and secondary seals areformed in the same fashion. Track 1025 adds additional rigidity andstrength to the IGU structure as well as a sealing function. In certainembodiments, the track is embedded in a traditional secondary sealantwithout also serving as a sealing element itself; in these embodiments,the track needs to traverse the entire perimeter of the IGU. In someembodiments, the track serves as the spacer, configured where aconventional spacer would be, along with a primary sealant between tracksurfaces and interior surfaces of the panes. In these embodiments, thereis only one spacer, the track, which serves as a wired spacer andprimary sealing element.

Track 1025 also includes rails, in this example in the form of wires,1030 and 1035, which provide electrical communication to bus bars 1015via wires, 1017. That is, wires 1017 connect bus bars 1015 to wires 1030and 1035 in track 1025. Track 1025 is described further in relation toFIG. 10B. FIG. 10A, in the bottom portion, shows only track 1025.Included is an expanded view of a corner portion of track 1025, showingdetail of a channel in which reside wires 1030 and 1035. In thisexample, wires 1030 and 1035 run all the way around the channel of track1025. In other embodiments, wires 1030 and 1035 run only in a portion(e.g., one side, two sides, or three sides) of track 1025. The rails ofthe track may be other than wires, so long as they are conductivematerial, although wires are convenient because they are common andeasily configured in a track, e.g., track 1025 may be an extrudedplastic material into which wires may be molded, or the wires may beinserted into the track after extrusion or molding.

FIG. 10B shows a cross-section D, as indicated in FIG. 10A, of track1025 showing the details of wires 1030 and 1035 and finer detail oftrack 1025. Track 1025 may be a non-conducting material, such as anextruded polymer, for example, that holds wires 1030 and 1035 in place.In one example, track 1025 is made of an extruded plastic channeledmaterial. The channeled material is cut and formed, e.g., ultrasonicallywelded, to form a unitary body as depicted. As shown in FIG. 10B, wires1030 and 1035 are located within recesses in track 1025 and, in thisexample, each wire is insulated on three sides. As mentioned, the wiresmay be inserted into the recesses after the track is fabricated. Track1025 includes two slots or channels, 1040 and 1050. Slot 1050 allows forelectrical connection of an electrical connector, e.g., from a windowcontroller to IGU 1000. Wires 1017 from bus bars 1015 of theelectrochromic pane 1010 may be housed in slot 1040. Wires 1017 may passthough the material of track 1025, e.g., passing from slot 1040 throughan aperture and into slot 1050, so that the each of the wires 1017 maycontact its respective wire 1030 or 1035. The aperture through whichwires 1017 pass may be sealed prior to fabrication of the IGU, or duringfabrication of the IGU, e.g., using adhesive sealant residing in slot1040. In one example, a sealant is applied to the gap between the wireand the aperture. Slot 1040 also may allow for additional wires and/orinterconnections to be made to the IGU.

In one example, track 1025 is assembled with wires 1017 being attachedto rails 1030 and 1035 prior to being attached to bus bars 1015. Thatis, one embodiment is a track including rails and wires connected to therails, the wires passing through the track such that the track, oncesandwiched between two panes of glass, optionally with an adhesivesealant, forms a hermetic seal. In one such embodiment, assembly of theIGU includes 1) attaching wires 1017 to the bus bars, and 2) thensimultaneously forming the primary and the secondary seal usingseparator 1020 and track 1025. Electrical connections may be made toelectrochromic pane 1010 with connector 1045. Connector 1045 may includea non-conducting body 1047 with two conducting tabs, 1055 and 1060. Inthis example, each of the two conducting tabs 1055 and 1060 is connectedto a single incoming wire, 1075. Each of the single wires may be coupledto a connector, as described herein, and ultimately connected to awindow controller. In this example, to establish electrical connection,connector 1045 is inserted into slot 1050 and then twisted about 90degrees so that each of the conducting tabs, 1055 and 1060, makescontact with a wire, 1035 and 1030, respectively. In some embodiments,to ensure that a correct wire is in contact with the correct tab, tabs1055 and 1060 and the recesses housing wires 1030 and 1035 areasymmetrical. As shown in FIG. 10B, tab 1060 is thicker than tab 1055.Further, the recess housing wire 1030 is smaller than the recess housingwire 1035. Connector 1045 enters slot 1050 and then, by virtue of theconfiguration of the recesses and tabs, the connector can be turned onlyso that tab 1060 contacts wire 1030 and tab 1055 contacts wire 1035.Varying tab thickness and recess size is one way to help to insure thatthe connector 1045 is in contact with the correct wires, but othermechanisms to achieve this are also possible. In embodiments where thetrack is the only spacer, e.g., configured as a conventional spacer,connector 1045 may or may not be configured to penetrate the secondarysealant in order to establish contact with the rails. Where theconnector 1045 is not configured to penetrate the secondary sealant tocontact the rails on track 1025, portions of the track 1025 may beexposed along one or more sides of the IGU so that connector 1045 canestablish contact directly, without having to penetrate the secondarysealant when inserted into the track. In the latter embodiment,secondary sealant is optionally applied to seal any open spacesremaining in the secondary seal, including those around installedconnector 1045.

One of ordinary skill in the art would appreciate that otherconfigurations of track 1025 are possible. For example, in oneembodiment, track 1025 is a linear track that is inserted along one sideof the IGU in the secondary sealing area. Depending upon the need, one,two, three or four such linear tracks, each along an independent side ofthe IGU, are installed in the IGU. In another embodiment, track 1025 isU-shaped, so that when installed in the secondary sealing area of theIGU, it allows electrical connection via at least three sides of theIGU.

FIGS. 11A and 11B show examples of diagrams of an IGU with a two-partspacer. The IGU, 1100, shown in FIG. 11A includes electrochromic lite,305, as depicted in FIG. 3A. Electrochromic lite 305 has bus bars, 310,fabricated on an electrochromic device (not depicted). In someembodiments, a bus bar may have a length about the length of theelectrochromic device. IGU 1100 includes a two-part spacer, including aninterior electrically non-conductive or insulating portion or spacer,1105, and an exterior metal portion or spacer, 1110. In someembodiments, non-conductive or insulating spacer 1105 and metal spacer1110 may have substantially rectangular cross sections. Non-conductiveor insulating spacer 1105 may be made from a polymeric material, aplastic material, or a foam material, for example. In some embodiments,the non-conductive or insulating spacer 1105 is a Triseal spaceravailable from Edgetech USA (of Cambridge, Ohio). Metal spacer 1110 maybe made from steel or stainless steel, for example. Metal spacer 1110may be a conventional spacer. One or more channels may be included inthe non-conductive or insulating spacer 1105 and in the metal spacer1110, for example to house the electrical connection the bus bars 310.

The non-conductive or insulating spacer 1105 may include a notch orrecess, 1115, to accommodate bus bar 310. The notch may form a channelin a side of the non-conductive or insulating spacer. An electrochromicdevice stack (not shown) is fabricated on glass lite 1130. Bus bar 310located on the electrochromic device stack makes electrical contact withone of the electrodes of the device. With non-conductive or insulatingspacer 1105 situated on top of bus bar 310, the risk of a short betweenbus bar 310 and metal spacer 1110 is reduced. An edge delete operationmay still be performed on glass lite 1130 down to the glass so thatmetal spacer 1110 does not contact the conductive electrodes of theelectrochromic device stack. The IGU primary seal is comprised ofinterfaces between glass lites 1130 and 1135 and primary seal material(e.g., PIB), 1140, and between primary seal material 1140 andnon-conductive or insulating spacer 1105 and metal spacer 1110.

In some embodiments, metal spacer 1110 may have about the same width asa conventional spacer; i.e., about 6 millimeters wide. In someembodiments, metal spacer 1110 may have a smaller width than aconventional spacer. For example, metal spacer 1110 may be about 4millimeters wide. Regardless of whether metal spacer 1110 has the samewidth or has a smaller width than a conventional spacer, the overalldesign of metal spacer 1110 may be similar in many regards to aconventional spacer.

A channel in one or more of the spacers may be used to house leads tothe bus bars. In one embodiment, metal spacer 1110 includes a raised(i.e., less tall) portion compared to non-conductive or insulatingspacer 1105. The raised portion of metal spacer 1110 effectively formsthe channel or mouse hole under which the bus bar leads passes to avoidelectrical contact with metal spacer 1110.

One advantage of the embodiments shown in FIGS. 11A and 11B is theincorporation of a relatively wide spacer including non-conductive orinsulating spacer 1105 and metal spacer 1110. The wide spacer providesadditional area for the primary seal as compared to a conventional metalspacer. As explained above, this additional seal area, which includesprimary seal material, can better protect the IGU interior from moistureand other ambient gasses, as well as prevent argon or other gas in theinterior of the IGU from escaping.

In some embodiments, non-conductive or insulating spacer 1105 includes adesiccant. In conventional IGUs, a desiccant is provided in the interiorof the metal spacer. Therefore, the metal spacer maintains its integrityin the IGU. For example, the metal spacer cannot include any holes tothe outside environment which would permit direct contact with thedesiccant when a desiccant is provided in the interior of the metalspacer. Typically, there are one or more holes used to introducedesiccant into the spacer, but these are sealed after the desiccant isintroduced.

The metal spacer may include holes to accommodate the wiring to connectthe electrochromic device bus bars with a power source. The wires can befed through the interior of the metal spacer. These holes may be sealedaround the wires to secure the desiccant's function in the metal spacer.FIG. 11A shows an example of a diagram of an IGU in which wiring for anelectrochromic device is inside the metal spacer. As shown in FIG. 11A,IGU 1150 includes electrochromic lite 305 with bus bars 310 fabricatedon an electrochromic device (not depicted). IGU 1150 includes a two-partspacer, including an interior non-conductive or insulating spacer 1105and an exterior metal spacer 1110. Wires 1155 are in electrical contactwith leads from bus bars 310. The wires are shown as being in theinterior of metal spacer 1110 and exit from metal spacer 1110, providingelectrical communication from the interior of IGU 1150 to the exteriorof IGU 1150. FIG. 11B shows an alternative embodiment, 1160, where thewires run in the secondary seal area, external to both spacers.

In some embodiments, the non-conductive or insulating spacer and themetal spacer may form a barrier between an exterior region and an interregion of the IGU. The metal spacer may include two holes, with a wirein electrical contact or communication with an electrode of anelectrochromic device passing through the first hole, though the hollowmetal spacer, and out of the second hole. The wire may provideelectrical communication from the exterior region of the IGU to theinterior region of the IGU.

The manufacturing advantage of the embodiment shown in FIG. 11A is thata spacer can be fabricated from the metal rectangular tubular portion inwhich the wires have already been fed. These metal rectangular tubularportions are normally provided as linear sections which are subsequentlybent into the rectangular shape of the spacer. If the wiring is providedin the linear sections prior to bending, the difficulty of feeding ametal wire through bent portions of the metal rectangular tubes isavoided. During manufacturing, and after the wiring is connected to thebus bar through the metal portion of the spacer, the holes in the metaltubular portion through which the wires are fed can be plugged with asealant, such as PIB, for example.

In some other embodiments, the entire spacer may be made from a materialthat is electrically non-conductive (i.e., electrically resistive orelectrically insulating) and therefore does not exhibit any of the threemodes of shorting illustrated in FIG. 4. Examples of such materials thatmay be used for a spacer include plastic materials, polymeric material,foam materials, and hard rubber materials. As an example, a foam spacersimilar to a Triseal spacer (Cambridge, Ohio), as mentioned above, maybe used. When an electrically resistive spacer is used, it may be widersuch that it occupies about 5 millimeters to about 10 millimeters of theouter edge of the IGU. This embodiment does not include a metal spacer,and the non-conductive material may be sufficiently rigid and strong toserve the role of a spacer. In some embodiments, the non-conductivespacer includes a desiccant and/or wiring, as described and illustratedin the context of FIGS. 11A and 11B.

In some embodiments, a metal spacer has an electrically non-conductiveor insulating outer coating (i.e., an electrically resistive outercoating) but may otherwise be similar in design and structure to aconventional spacer. In some embodiments, the metal spacer may have asubstantially rectangular cross section. In some embodiments, thenon-conductive outer coating may be on at least one side of thesubstantially rectangular cross section of the metal spacer. In someembodiments, the non-conductive outer coating may be on all four sidesof the substantially rectangular cross section of the metal spacer. Insome embodiments, the metal spacer may include a channel configured toaccommodate an electrode of an optically switchable device on one of theglass lites.

For example, one embodiment is metal spacer coated on one or more sideswith an insulating (non-electrically conductive) coating. The insulatingcoating may be a paint or polymeric material such aspolytetrafluoroethylene or similar material. The spacer is used alongwith a primary sealant material as described herein. The spacer mayinclude a channel and/or a notch as described herein. In one embodiment,the spacer includes one or more connector keys as described herein. Inone embodiment, the spacer is coated on all sides; in anotherembodiment, the spacer is coated on only the sides proximate the bus barand/or bus bar lead.

Although the foregoing embodiments have been described in some detail tofacilitate understanding, the described embodiments are to be consideredillustrative and not limiting. It will be apparent to one of ordinaryskill in the art that certain changes and modifications can be practicedwithin the scope of the appended claims.

What is claimed is:
 1. An insulated glass unit (IGU) comprising: a firstglass substrate; a second glass substrate over the first glasssubstrate; an electrochromic device positioned on or over the firstglass substrate or on or over the second glass substrate; two bus barselectrically coupled to the electrochromic device; a spacer positionedbetween the first and second glass substrates proximate the periphery ofthe first and second glass substrates, wherein the spacer and the firstand second glass substrates define an interior volume of the IGU; andone or more conductors passing through the spacer to provide electricalpower from an external power source to the bus bars coupled to theelectrochromic device.
 2. The IGU of claim 1, wherein the spacercomprises a track having an interior recess for one or more electricalconnections on an interior volume of the IGU defined by the first andsecond glass substrates and the spacer.
 3. The IGU of claim 1, whereinthe spacer is hollow, and wherein the one or more conductors enter thehollow spacer at a first location, pass within an interior volume of thespacer, and exit the spacer at a second location.
 4. The IGU of claim 1,wherein the spacer is at least partially filled with an insulativematerial, and wherein the one or more conductors enter the spacer at afirst location, pass within the interior of the spacer for a distance,and exit the spacer at a second location.
 5. The IGU of claim 4, whereinthe insulative material comprises a foam.
 6. The IGU of claim 1, furthercomprising one or more holes in the spacer through which the one or moreconductors pass.
 7. The IGU of claim 1, wherein the spacer comprises aconductive portion and an insulative connector key that joins opposingends of the conductive portion together, and wherein the one or moreconductors passing through the spacer traverse the spacer at theinsulative connector key.
 8. The IGU of claim 1, wherein the spacercomprises a track having interior recesses for two or more electricalconnections on the interior of the track and one or more holes throughthe track for establishing a pass-through electrical connection betweentwo or more electrical connections from a volume external to theinterior volume.
 9. The IGU of claim 1, further comprising a seal in ahole of the spacer through which the one or more conductors pass.
 10. Aninsulated glass unit (IGU) comprising: a first glass substrate; a secondglass substrate over the first glass substrate; an electrochromic devicepositioned on or over the first glass substrate or on or over the secondglass substrate; two bus bars electrically coupled to the electrochromicdevice; a spacer positioned between the first and second glasssubstrates proximate the periphery of the first and second glasssubstrates, wherein the spacer separates an interior volume of the IGUfrom an exterior volume of the IGU located outside of the spacer; andone or more electrical conductors passing through or under the spacer toprovide electrical power from power source located in the exteriorvolume to the bus bars.
 11. The IGU of claim 10, wherein the spacercomprises a track having interior recesses for two or more electricalconnections on the interior of the track.
 12. The IGU of claim 10,wherein the spacer comprises an indented portion such that the channelis defined on one side by the first or second glass substrate or a layerof material thereon.
 13. The IGU of claim 12, wherein the channel isdefined on remaining sides by the indented portion of the spacer as thechannel passes from the volume external to the IGU to the interiorvolume of the IGU.
 14. The IGU of claim 10 wherein the spacer comprisesone or more exterior recesses for two or more electrical connections onthe exterior of the track.
 15. The IGU of claim 10 further comprising aseal in a hole of the spacer through which one or more conductorspasses.
 16. The IGU of claim 10, further comprising a controller coupledto the IGU and configured to drive an electrochromic transition of theelectrochromic device on the IGU.
 17. The IGU of claim 10, wherein thespacer is filled with a substantially insulative material, and whereinthe one or more conductors enter the spacer at a first location and passwithin the interior of the spacer before exiting the spacer at a secondlocation.
 18. An insulated glass unit (IGU) comprising: a firstsubstantially transparent substrate having an electrochromic devicedisposed on a surface; two bus bars electrically connected with theelectrochromic device; a second substantially transparent substrate; aspacer at least partially filled with and insulative material andpositioned proximate to the periphery of the first and secondsubstantially transparent substrates and between the first and thesecond substantially transparent substrates, wherein an interior volumeof the IGU is defined between the first and second substantiallytransparent substrates and enclosed by the spacer; and one or moreelectrical connections for delivering power to the bus bars.
 19. The IGUof claim 18, wherein the spacer comprises a track having an interiorrecess for one or more electrical conductors within the spacer.
 20. TheIGU of claim 18, wherein the electrical connection for delivering powerto the bus bars comprises a conductor that passes from the exteriorvolume of the IGU, through the channel, and into the interior volume ofthe IGU to make electrical contact with one or more of the bus bars, thebus bars being positioned such that they do not extend into the exteriorvolume of the IGU.
 21. The IGU of claim 18, wherein the electricalconnection for delivering power to the bus bars is a bus bar leadoriented substantially perpendicular to the bus bar with which the busbar lead is associated.